Background: A significant fraction of patients with ulcerative colitis (UC) is not sufficiently controlled with conventional anti-inflammatory or immunosuppressive therapy or suffers from therapy related side effects. For several diseases interest in the therapeutic potential of polyphenols has risen in recent years. Anthocyanines, highly abundant in bilberries, were shown to have antioxidative and antiinflammatory effects. We therefore investigated the therapeutic potential of a peroral bilberry preparation in mild to moderate active UC.

Methods: In an open pilot trial with a total follow-up of 9 weeks the effect of a daily standardised anthocyanine-rich bilberry preparation was tested in 13 patients with mild to moderate UC (CAI 48). Clinical, biochemical, endoscopic and histologic (sigmoidoscopy before and after the intake phase) parameters were assessed.

Results: At the end of the treatment interval (6 weeks) 63.4% of patients achieved remission (CAI <4), the primary endpoint, while 90.9% of patients showed a response (drop of CAI ≥3 points). In all patients a decrease in total Mayo Score was detected. A significant sustained beneficial effect (46.2% respectively 72.7% for remission and response) was found at the end of the follow up period. Faecal calprotectin levels significantly decreased during the treatment phase (baseline: mean 778 ug/g, range 1921790 ug/g; end of treatment: mean 373 ug/g, range <303027 ug/g), including 4 patients achieving undetectable levels at end of treatment. However, an increase was observed after cessation of bilberry intake. In addition, a decrease in endoscopically (endoscopic Mayo Score) and histologically (Riley) indices confirmed the beneficial effects of the bilberry preparation.

Conclusions: This is the first report on the promising therapeutic potential of a standardised anthocyanine-rich bilberry preparation in UC. The results, although limited by the small patient number and the open study design, clearly indicate a therapeutic potential of bilberries in UC. Further studies on mechanisms and randomized clinical trials are warranted.